Method, apparatus, and system for data synchronization

ABSTRACT

A method, an apparatus, and a system for data synchronization are disclosed. The method includes: receiving a parameter value change notification message which carries a parameter change event and/or a digest of a specific parameter; and synchronizing data according to the parameter value change notification message. The synchronizing the data includes synchronizing the data in a parameter change record table stored in a Customer Premises Equipment (CPE). An Auto-Configuration Server (ACS) includes a receiving unit and a synchronizing unit. In this way, the requirement on the ACS is lowered and the burden of the ACS is relieved.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Patent ApplicationNo. PCT/CN2009/074522, filed on Oct. 20, 2009, which claims priority toChinese Patent Application No. 200810173571.X, filed on Nov. 6, 2008,both of which are hereby incorporated by reference in their entireties.

FIELD OF THE INVENTION

The present invention relates to communication technologies, and inparticular, to a method, an apparatus and a system for datasynchronization.

BACKGROUND OF THE INVENTION

Digital Subscriber Line (DSL) is a broadband access technology.Applications based on broadband access technologies, such Voice overInternet Protocol (VoIP) and Internet Protocol Television (IPTV),require IP-based terminal devices on the DSL.

The IP-based terminal devices are known as Customer Premises Equipment(CPE). An Auto-Configuration Server (ACS) synchronizes data with theCPE, and modifies and sets parameter values of the CPE according to thesynchronized data so as to achieve the purpose of auto configuration ofthe CPE.

In a prior art, the synchronization of data between the ACS and the CPEincludes: when the value of a parameter with the attribute “Notify ACSof Changes” in the CPE changes, the CPE sets up a connection with theACS and reports a parameter value change event that carries a parameterlist to the ACS, where the parameter list includes all parameter valuesof the CPE. The ACS synchronizes the parameter values included in theparameter list reported by the CPE. The event will be dropped when theCPE is restarted.

During the research on the prior art, the inventor finds at least thefollowing disadvantages: the synchronization of data on the CPE to theACS adds the burden on the ACS. Specifically, when the value of aparameter with the attribute “Notify ACS of Changes” in the CPE changes,the CPE sets up a connection with the ACS immediately and reports thespecific changes, despite whether the ACS is busy in processing othertransactions. The time when the changes are reported is decided by theCPE while the ACS cannot decide whether to receive the changes accordingto its need.

SUMMARY OF THE INVENTION

Accordingly, embodiments of the present invention provide a method, anapparatus, and a system for data synchronization to relieve the burdenof the ACS.

A method for data synchronization provided in an embodiment of thepresent invention includes:

receiving a parameter value change notification message which carries aparameter change event and/or a digest of a specific parameter; and

synchronizing data according to the parameter value change notificationmessage, where the synchronizing the data includes: synchronizing datain a parameter change record table stored in a CPE.

Another method for data synchronization where a parameter change recordtable is created provided in an embodiment of the present inventionincludes:

when a value of a specific parameter changes, storing parameter changeinformation in the parameter change record table, and generating aparameter change event and/or calculating a digest of the specificparameter according to requirements of an ACS; and

reporting a parameter value change notification message that carries theparameter change event and/or the digest of the specific parameter tothe ACS.

An ACS provided in an embodiment of the present invention includes:

a receiving unit, configured to receive a parameter value changenotification message which carries a parameter change event and/or adigest of a specific parameter; and

a synchronizing unit, configured to synchronize data according to theparameter value change notification message received by the receivingunit, wherein the synchronizing the data includes synchronizing data ina parameter change record table according to the parameter change recordtable stored in a CPE.

A CPE provided in an embodiment of the present invention includes:

a creating unit, configured to create a parameter change record table;

a storing unit, configured to store parameter change information in theparameter change record table created by the creating unit when a valueof a specific parameter changes;

a parameter unit, configured to, when the value of the parameterchanges, generate a parameter change event, and/or calculate a digest ofthe specific parameter; and

a reporting unit, configured to report a parameter value changenotification message that carries the parameter change event generatedand/or the digest of the specific parameter calculated by the parameterunit to an ACS.

A system for data synchronization provided in an embodiment of thepresent invention includes a CPE and an ACS, where:

the CPE communicates with the ACS and is configured to: create aparameter change record table, and when the value of a specificparameter changes, store parameter change information in the parameterchange record table, generate a parameter change event, and/or calculatea digest of the specific parameter according to requirements of the ACS,and report a parameter value change notification message that carriesthe parameter change event and/or the digest of the specific parameterto the ACS.

In the embodiments of the present invention, the CPE only notifies theserver of the occurrence of a parameter change, but not the specificchange, and the ACS synchronizes data in the parameter change recordtable according to the parameter change record table stored in the CPE.Therefore, the requirement on the ACS is lowered and the burden of theACS is relieved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart of a method according to an embodiment of thepresent invention;

FIG. 2 is a flowchart of a method according to an exemplary embodimentof the present invention;

FIG. 3 is a structure diagram of an ACS according to an embodiment ofthe present invention;

FIG. 4 is a structure diagram of an ACS according to an exemplaryembodiment of the present invention;

FIG. 5 is a structure diagram of a CPE according to an embodiment of thepresent invention; and

FIG. 6 is a structure diagram of a CPE according to an exemplaryembodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

To better explain the technical features and benefits of the embodimentsof the present invention, the embodiments of the present invention willbe described in detail with reference to the accompanying drawings.

FIG. 1 is a flowchart of a method according to an embodiment of thepresent invention. The method for data synchronization includes thefollowing steps:

Step 101: Receive a parameter value change notification message, whichcarries a parameter change event and/or a digest of a specificparameter.

Step 102: Synchronize data according to the parameter value changenotification message, where the synchronizing the data includessynchronizing the data in a parameter change record table according tothe parameter change record table stored in the CPE.

It can be seen that, the CPE only notifies the server of the occurrenceof a parameter change, but not the specific change. The ACS synchronizesthe data in the parameter change record table according to the parameterchange record table stored in the CPE. That is, the ACS can determinewhen to read the parameter change record table stored in the CPEaccording to the condition of the ACS, so that the ACS can synchronizethe parameter changes of the CPE more flexibly. Therefore, therequirement on the ACS is lowered and the burden of the ACS is relieved.The steps shown in FIG. 1 are described in detail with reference toexemplary embodiments.

In the embodiments of the present invention, the definition of theparameter value change notification in the parameter attribute structureis modified.

In the prior art, the definitions of the parameter value changenotification in the parameter attribute structure are described in Table1.

TABLE 1 Parameter Parameter Name Type Parameter Description ParameterCharacter Indicates the name of the parameter that the Name (256)attribute is defined for. The name must be a full name of the parameterinstead of a partial path parameter name. Notification Integer Indicateswhether the CPE needs to include a Attribute [0:2] value change of thespecified parameter in an Inform message and whether the CPE needs toset up a session with the ACS to report the parameter value changemessage when the value of the specified parameter changes. Thedefinitions of the attribute values are as follows: 0 = NotificationOff. For the specified parameter, the CPE does not notify the ACS of achange of the parameter value. 1 = Passive notification. When the valueof the specified parameter changes, the CPE must include the newparameter value in the parameter list and include the parameter list inan Inform message when the next session is set up. 2 = Activenotification. When the value of the specified parameter changes, the CPEmust set up a session with the ACS and include a parameter value changeevent in the parameter list carried in an Inform message.

In the embodiments of the present invention, after the definitions ofthe parameter value change notification in the parameter attributestructure are modified, the new definitions of the parameter valuechange notification in the parameter attribute structure are describedin Table 2.

TABLE 2 Parameter Parameter Name Type Parameter Description ParameterCharacter Indicates the name of the parameter that the Name (256)attribute is defined for. The name must be a full name of the parameterinstead of a partial path parameter name. Notification Integer Indicateswhether the CPE needs to include a Attribute [0:2] value change of thespecified parameter in an Inform message and whether the CPE needs toset up a session with the ACS to report the parameter value changemessage when the value of the specified parameter changes. Thedefinitions of the attribute values as follows: 0 = Notification Off.For the specified parameter, the CPE does not notify the ACS of a changeof the parameter value. 1 = Passive notification. When the value of thespecified parameter changes, the CPE includes the parameter change in aparameter change record table and includes the parameter value changeevent in an Inform message when the next session is set up. However, theCPE must not put a new parameter value into the parameter list. 2 =Active notification. When the value of the specified parameter changes,the CPE includes the parameter change in a parameter change recordtable, and must set up a session with the ACS and include the parametervalue change event in an Inform message. However, the CPE must not put anew parameter value into the parameter list.

From a comparison between Table 1 and Table 2, in the method embodimentsof the present invention, it is necessary to create a parameter changerecord table and include the new parameter value in the parameter changerecord table, instead of including the new parameter value in aparameter list. The form of the parameter change record table is listedin Table 3.

TABLE 3 New Parameter Parameter Name Value Time of Change

It should be noted that Table 3 is only an exemplary implementation ofthe method provided in the embodiments of the present invention. Theparameter change record table provided in the embodiments of the presentinvention is not limited to this form. For example, the table may recordinformation such as the old parameter value.

In the method embodiments of the present invention, when the value of aparameter marked as passive notification or active notification changes,the CPE stores the change-related information (for example, the newparameter value and the time of parameter change) in the parameterchange record table shown in Table 3. For a parameter marked as passivenotification, the CPE parameter value change event is included in theInform message when the next session is set up. For a parameter markedas active notification, the CPE may set up a connection with the ACSimmediately and include the CPE parameter value change event in theInform message. For a parameter marked as active notification, the CPEmay also include the CPE parameter value change event in the Informmessage when the next session is set up, as in the case of a parametermarked as passive notification, instead of setting up a connection withthe ACS immediately.

With the definitions of the parameter value change notification in theparameter attribute structure and the created parameter change recordtable provided in the method embodiments of the present invention, theACS can synchronize data changed in the CPE and needed by the ACS to theACS. FIG. 2 is a flowchart of the method according to an embodiment ofthe present invention. The method for data synchronization includes thefollowing steps:

Step 201: When the value of a parameter with an attribute “Notify ACS ofChanges” in the CPE changes, the CPE stores the change-relatedinformation, for example, the new parameter value and the time ofparameter value change, in a parameter change record table, andgenerates a 4VALUECHANGE event, and/or calculates a digest (Hash value)of the parameter with the attribute “Notify ACS of Changes” according torequirements of the ACS.

Step 202: The CPE reports a parameter value change notification messagethat carries the 4VALUECHANGE event and/or the Hash value to the ACS.

It should be specially noted that, in step 202, if the CPE reports the4VALUECHANGE event, the 4VALUECHANGE event does not include a parameterlist. The CPE only notifies the ACS of the occurrence of a parameterchange, but not the specific parameter change information.

Step 203: The ACS receives the parameter value change notificationmessage that carries the 4VALUECHANGE event and/or the Hash valuereported by the CPE.

In step 203, if the ACS receives only the 4VALUECHANGE event reported bythe CPE, the ACS may know that the value of the parameter with theattribute “Notify ACS of Changes” changes according to the 4VALUECHANGEevent. If the ACS receives both the 4VALUECHANGE event and the Hashvalue, the ACS compares the currently received Hash value and the lastreceived Hash value to further determine that the value of the parameterwith the attribute “Notify ACS of Changes” changes. If the ACS receivesonly the Hash value, the ACS may know whether the value of the parameterwith the attribute “Notify ACS of Changes” changes by comparing thecurrently received Hash value and the last received Hash value. If thevalue of the parameter with the attribute “Notify ACS of Changes”changes, step 204 is executed; if the value of the parameter with theattribute “Notify ACS of Changes” does not change, the procedure ends.

Step 204: The ACS decides when to synchronize data of the changedparameter value in the CPE according to the load condition of the ACS.

In step 204, the ACS may decide to synchronize the data of the changedparameter value in the CPE immediately, or decide to synchronize thedata later.

When the ACS performs data synchronization, the ACS sends a command tothe CPE to read all data in the parameter change record table in theCPE, and synchronizes the data in the parameter change record table tothe ACS. After the data in the parameter change record table issynchronized to the ACS, the CPE deletes the synchronized data. Inaddition, in steps 201 to 204, the 4VALUECHANGE event and the data inthe parameter change record table can be stored continuously after theCPE is restarted.

From the above description, the CPE only notifies the ACS of theoccurrence of a parameter change, but not the specific change, and theACS decides when to synchronize data to the ACS according to its owncondition. For non-emergency data, the ACS may choose to performsynchronization at night or in hours with light load. Therefore, therequirement on the ACS is lowered and the burden of the ACS is relieved.In the case of a parameter marked as active notification, the CPEincludes a CPE parameter value change event in the Inform message whenthe next session is set up, instead of setting up a connection with theACS immediately. This further reduces the burden of the ACS.

In addition, because the 4VALUECHANGE event and the data in theparameter change record table can be stored continuously after the CPEis restarted, the ACS can synchronize the data accurately.

FIG. 3 is a structure diagram of an ACS according to an embodiment ofthe present invention. The ACS includes:

a receiving unit 301, configured to receive a parameter value changenotification message, where the parameter value change notificationmessage carries a parameter change event and/or a digest of a specificparameter; and

a synchronizing unit 302, configured to synchronize data according tothe parameter value change notification message, where the synchronizingthe data includes synchronizing the data in a parameter change recordtable according to the parameter change record table stored in the CPE.

It can be seen that, the CPE only notifies the ACS of the occurrence ofa parameter change, but not the specific change. The ACS synchronizesthe data in the parameter change record table according to the parameterchange record table stored in the CPE. Therefore, the requirement on theACS is lowered and the burden of the ACS is relieved. With reference tothe method provided in the exemplary embodiment, FIG. 4 is a structurediagram of an ACS according to an exemplary embodiment of the presentinvention. On the basis of FIG. 3, the ACS further includes:

an analyzing unit 303, configured to decide when to synchronize a valueof the changed parameter according to the parameter value changenotification message received by the receiving unit 301 and according toa current load;

a comparing unit 304, configured to compare the digest received by thereceiving unit 301 with a last received digest; and

a judging unit 305, configured to judge whether the value of thespecific parameter in the CPE changes according to the comparisonperformed by the comparing unit 304.

The synchronizing unit 302 is further configured to synchronize the dataaccording to the parameter value change notification message received bythe receiving unit 301 and according to the judgment of the judging unit305.

FIG. 5 is a structure diagram of a CPE according to an embodiment of thepresent invention. As shown in FIG. 5, the CPE includes:

a creating unit 401, configured to create a parameter change recordtable;

a storing unit 402, configured to store parameter change information inthe parameter change record table created by the creating unit 401 whena value of a specific parameter changes;

a parameter unit 403, configured to, when the value of the parameterchanges, generate a parameter change event, and/or calculate a digest ofthe specific parameter; and

a reporting unit 404, configured to report a parameter value changenotification message that carries the parameter change event generatedand/or the parameter digest calculated by the parameter unit 403 to anACS.

With reference to the method provided in the exemplary embodiment, FIG.6 is a structure diagram of a CPE according to an exemplary embodimentof the present invention, where the parameter unit 403 includes:

a generating unit 403-1, configured to generate the parameter changeevent when the value of the parameter changes.

Or, the parameter unit 403 includes:

a calculating unit 403-2, configured to calculate the digest of thespecific parameter according to requirements of the ACS.

Or, the parameter unit 403 includes:

a generating unit 403-1, configured to generate the parameter changeevent when the value of the parameter changes; and

a calculating unit 403-2, configured to calculate the digest of thespecific parameter according to requirements of the ACS.

The operations performed by the above units are described in detail withreference to the exemplary embodiment of the method.

Where the parameter unit 403 includes only the generating unit 403-1:when the value of a parameter with the attribute “Notify ACS of Changes”in the CPE changes, the storing unit 402 of the CPE stores thechange-related information, for example, the new parameter value and thetime of parameter value change, in the parameter change record tablecreated by the creating unit 401, and the generating unit 403-1generates a 4VALUECHANGE event. The reporting unit 404 reports aparameter value change notification message that carries the4VALUECHANGE event to the ACS.

For a parameter marked as passive notification, the CPE parameter valuechange event is included in the Inform message when the next session isset up. For a parameter marked as active notification, the CPE may setup a connection with the ACS immediately and include the CPE parametervalue change event in the Inform message. For a parameter marked asactive notification, the CPE may also include the CPE parameter valuechange event in the Inform message when the next session is set up, asin the case of a parameter marked as passive notification, instead ofsetting up a connection with the ACS immediately.

The receiving unit 301 of the ACS receives the parameter value changenotification message from the CPE, and the analyzing unit 302 decideswhen to synchronize the data of the changed parameter value according tothe parameter value change notification message received by thereceiving unit 301 and the current load. The synchronizing unit 302synchronizes the data at the time decided by the analyzing unit 303, andwhen performing the data synchronization, the synchronizing unit 302reads the parameter change record table stored in the CPE andsynchronizes the data in the parameter change record table.

Where the parameter unit 403 includes only the calculating unit 403-2:the calculating unit 403-2 of the CPE calculates the Hash value of aparameter with the attribute “Notify ACS of Changes”. If the calculatingunit 403-2 of the CPE calculates the Hash value of the parameter withthe attribute “Notify ACS of Changes”, the parameter value changenotification message received by the receiving unit 301 carries the Hashvalue. The comparing unit 304 compares the Hash value currently receivedby the receiving unit 301 currently with the Hash value last received;the judging unit 305 judges whether the value of the parameter with theattribute “Notify ACS of Changes” in the CPE changes according to thecomparison performed by the comparing unit 304. The analyzing unit 303decides when to synchronize the data of the changed parameter valueaccording to the judgment of the judging unit 305 and the current load.The synchronizing unit 302 synchronizes the data at the time decided bythe analyzing unit 303, and when performing the data synchronization,the synchronizing unit 302 reads the parameter change record tablestored in the CPE and synchronizes the data in the parameter changerecord table.

Where the parameter unit 403 includes both the generating unit 403-1 andthe calculating unit'403-2: when the value of a parameter with theattribute “Notify ACS of Changes” in the CPE changes, the storing unit402 of the CPE stores the change-related information, for example, thenew parameter value and the time of parameter value change, in theparameter change record table created by the creating unit 401, and thegenerating unit 403-1 generates a 4VALUECHANGE event. The calculatingunit of the CPE calculates the Hash value of the parameter with theattribute “Notify ACS of Changes”.

The reporting unit 404 reports a parameter value change notificationmessage that carries the 4VALUECHANGE event and the Hash value of theparameter with the attribute “Notify ACS of Changes” to the ACS. Thereceiving unit 301 of the ACS receives the parameter value changenotification message from the CPE. It is known that the value of theparameter with the attribute “Notify ACS of Changes” changes accordingto the 4VALUECHANGE event. The comparing unit 304 compares the Hashvalue currently received by the receiving unit 301 with the Hash valuelast received; the judging unit 305 further judges whether the value ofthe parameter with the attribute “Notify ACS of Changes” in the CPEchanges according to comparison performed by the comparing unit 304.

The analyzing unit 303 decides when to synchronize the data of thechanged parameter value according to the judgment of the judging unit305 and according to the current. The synchronizing unit 302synchronizes the data at the time decided by the analyzing unit 303, andwhen performing the data synchronization, the synchronizing unit 302reads the parameter change record table stored in the CPE andsynchronizes the data in the parameter change record table.

From the above description, it is known that the CPE only notifies theACS of the occurrence of a parameter change, but not the specificchange, and the ACS decides when to synchronize the changed data to theACS according to its own condition. Therefore, the requirement on theACS is lowered and the burden of the ACS is relieved. In the case of aparameter marked as active notification, the CPE includes a parametervalue change event in the Inform message when the next session is setup, instead of setting up a connection with the ACS immediately. Thisfurther reduces the burden of the ACS.

In addition, because the 4VALUECHANGE, event and the data in theparameter change record table can be stored continuously after the CPEis restarted, the ACS can synchronize the data accurately.

A system for data synchronization according to an embodiment of thepresent invention includes:

a CPE, which communicates with an ACS, and is configured to: create aparameter change record table, and when a value of a specific parameterchanges, store parameter change information in the parameter changerecord table, generate a parameter change event, and/or calculate adigest of the specific parameter according requirements of the ACS, andreport a parameter value change notification message that carries theparameter change event and/or the digest of the specific parameter tothe ACS.

The operations performed by the CPE and the ACS are the same asdescribed in the embodiments of the method.

Finally, the term “include”, “comprise”, or any other variant indicatesa non-exclusive inclusion, so that a process, method, object, or devicethat includes a series of elements includes not only these elements butalso other elements that are not listed, or elements that are inherentto the process, method, object, or device. In the case of no furtherlimitations, an element preceded by “including one” does not exclude thesituation that the process, method, object, or device which includes theelement includes other same elements.

Based on the descriptions of the forming embodiments, those skilled inart will be clear that the embodiments of the present invention can beimplemented by software and a necessary general hardware platform orimplemented by hardware, but in most cases, the embodiment of thepresent invention are implemented by the former. Based on suchunderstanding, all or a part of the technical solutions of the presentinvention that contribute to the prior art can be embodied by a softwareproduct, which can be stored in a computer readable storage medium, suchas a Read Only Memory (ROM), a Random Access Memory (RAM), a magneticdisk, or a Compact Disk-Read Only Memory (CD-ROM). The software productincludes a number of instructions that enable a computer device (whichmay be a personal computer, a server, or a network device) to executethe method according to the embodiments of the present invention or acertain part of an embodiment of the present invention.

The method, apparatus, and system for data synchronization provided bythe invention have been described in detail in the above. Specificexamples are illustrated in the specification to elaborate the principleand implementation of the present invention, and the illustration of theembodiments is intended to help to understand the method and core ideaof the present invention. Furthermore, persons of ordinary skill in theart can make variations to the embodiments and application scopeaccording to the idea of the present invention. Therefore, the contentof the specification should not be construed as limitation to thepresent invention.

1. A method for data synchronization, comprising: receiving a parameter value change notification message, wherein the parameter value change notification message carries a parameter change event and/or a digest of a specific parameter; and synchronizing data according to the parameter value change notification message, wherein the synchronizing the data comprises: synchronizing data in a parameter change record table stored in a Customer Premises Equipment (CPE).
 2. The method for data synchronization according to claim 1, wherein before the synchronizing the data according to the parameter value change notification message, the method further comprises: deciding when to synchronize a value of the changed parameter according to a current load.
 3. The method for data synchronization according to claim 1, wherein the step of receiving the parameter value change notification message comprises: comparing the digest of the specific parameter with a last received digest of the specific parameter, judging whether a value of the specific parameter in the CPE changes according to the comparison, if the value changes, synchronizing the data according to the parameter value change notification message, and if the value does not change, ending the process.
 4. A method for data synchronization, wherein a parameter change record table is created, comprising: when a value of a specific parameter changes, storing change information in the parameter change record table, and generating a parameter change event and/or calculating a digest of the specific parameter according to requirements of an Auto-Configuration Server (ACS); and reporting a parameter value change notification message that carries the parameter change event and/or the digest of the specific parameter to the ACS.
 5. The method for data synchronization according to claim 4, wherein the step of reporting the parameter value change notification message that carries the parameter change event and/or the digest of the specific parameter to the ACS comprises: reporting the parameter value change notification message that carries the parameter change event and/or the digest of the specific parameter to the ACS in a next session, wherein the parameter value change notification message is contained in a notification message of the next session.
 6. The method for data synchronization according to claim 4, wherein the step of reporting the parameter value change notification message that carries the parameter change event and/or the digest of the specific parameter to the ACS comprises: creating a session with the ACS; and reporting the parameter value change notification message that carries the parameter change event and/or the digest of the specific parameter to the ACS.
 7. An Auto-Configuration Server (ACS), comprising: a receiving unit, configured to receive a parameter value change notification message, wherein the parameter value change notification message carries a parameter change event and/or a digest of a specific parameter; and a synchronizing unit, configured to synchronize data according to the parameter value change notification message received by the receiving unit, wherein the synchronizing the data comprises synchronizing the data in a parameter change record table according to the parameter change record table stored in a Customer Premises Equipment (CPE).
 8. The ACS according to claim 7, further comprising: an analyzing unit, configured to decide when to synchronize a value of the changed parameter according to the parameter value change notification message received by the receiving unit and according to a current load.
 9. The ACS according to claim 8, further comprising: a comparing unit, configured to compare the digest received by the receiving unit with a last received digest; and a judging unit, configured to judge whether the value of the specific parameter in the CPE changes according to the comparison performed by the comparing unit; wherein the synchronizing unit is configured to synchronize the data according to the parameter value change notification message received by the receiving unit and according to the judgment of the judging unit.
 10. A Customer Premises Equipment (CPE), comprising: a creating unit, configured to create a parameter change record table; a storing unit, configured to store parameter change information in the parameter change record table created by the creating unit when a value of a specific parameter changes; a parameter unit, configured to, when the value of the parameter changes, generate a parameter change event when the value of the parameter changes, and/or calculate a digest of the specific parameter; and a reporting unit, configured to report a parameter value change notification message that carries the parameter change event generated and/or the digest of the specific parameter calculated by the parameter unit to an Auto-Configuration Server (ACS).
 11. The CPE according to claim 10, wherein the parameter unit comprises: a generating unit, configured to generate the parameter change event when the value of the parameter changes.
 12. The CPE according to claim 10, wherein the parameter unit comprises: a calculating unit, configured to calculate the digest of the specific parameter according to requirements of the ACS.
 13. The CPE according to claim 10, wherein the parameter unit comprises: a generating unit, configured to generate the parameter change event when the value of the parameter changes; and a calculating unit, configured to calculate the digest of the specific parameter according to requirements of the ACS.
 14. A system for data synchronization, comprising a Customer Premises Equipment (CPE) and an Auto-Configuration Server (ACS), wherein: the CPE communicates with the ACS, and is configured to: create a parameter change record table, and when a value of a specific parameter changes, store parameter change information in the parameter change record table, generate a parameter change event, and/or calculate a digest of the specific parameter according requirements of the ACS, and report a parameter value change notification message that carries the parameter change event and/or the digest of the specific parameter to the ACS. 